ZyXEL Communications 652 Network Router User Manual


 
Prestige 652 ADSL Security Router
16-16 Filter Configuration
Figure 16-15 Sample Filter — Menu 21.1.9.1
Step 5. Type 1 to configure the first filter rule. Make the entries in this menu as shown next.
When you press [ENTER] to confirm, the following screen appears. Note that there is only one filter rule in
this set.
Menu 21.1.9.1 - TCP/IP Filter Rule
Filter #: 9,1
Filter Type= TCP/IP Filter Rule
Active= Yes
IP Protocol= 6 IP Source Route= No
Destination: IP Addr= 0.0.0.0
IP Mask= 0.0.0.0
Port #= 23
Port # Comp= Equal
Source: IP Addr= 0.0.0.0
IP Mask= 0.0.0.0
Port #=
Port # Comp= None
TCP Estab= No
More= No Log= None
Action Matched= Drop
Action Not Matched= Forward
Press ENTER to Confirm or ESC to Cancel:
Press [SPACE BAR] to choose
this filter rule type. The first
filter rule type determines all
subsequent filter types within a
set.
Select Yes to make the rule
active.
6 is the TCP protocol.
The port number for the telnet
service (TCP protocol) is 23.
See RFC-1060 for port
numbers of well-known
services.
Select Equal
here as we are
looking for
packets going to
port 23 only.
There are no
more rules to
check.
Select Drop here so that
the packet will be
dropped if its destination
is the telnet port.
Select Forward here so that the packet will be
forwarded if its destination is not the telnet port and
there are no more rules in this filter set to check.
Select Next if there are more rules to check.